I haven’t seen one on each floor, either, but that’s still not as convenient as one in the room that’s yours so you can run it while you’re out to dinner or overnight while you sleep. It’s shared so you have to plan around it.

I have stayed at many hotels of varying degrees of quality all over the U.S., and I have never, not once, seen the laundry being used. It’s always been available.

They're not common but the hotel I often stay in London has a laundry room that I use pretty routinely on longer trips.

On my trips outside the US, the hotel laundry rooms are usually busy. Enough that many of the hotels show individual machine status from a top-level page in the TV menu.